Field of the Invention
The present invention generally relates to ophthalmic solutions and uses thereof. The ophthalmic solutions treat glaucoma and conjunctival inflammation in human subjects.
Description of the Related Technology
Glaucoma is one of the leading causes of blindness worldwide. In the U.S. there are approximately 2.5 million sufferers of glaucoma. Glaucoma refers to a group of diseases that damage the eye's optic nerve and can result in vision loss and eventually, blindness. Glaucoma is caused by an increase in the intraocular pressure (TOP), which eventually leads to optic nerve degeneration and blindness.
In the front of the eye is an anterior chamber, wherein a clear fluid flows in and out continuously through a drainage angle at the meeting point of the iris and the cornea. When the drainage angle is affected, fluid does not drain fast enough or does not drain at all, causing a buildup in eye pressure. High pressure may cause damages to optic nerves, which in turn causes vision loss and blindness.
High blood pressure is a contributing factor to glaucoma. However, glaucoma may happen even without pressure buildup in the eye chamber. Glaucoma affects different ethnic groups differently. In the African-American population, glaucoma is the leading cause of blindness. The Hispanic population is also affected by glaucoma more than other ethnic groups.
Age-related macular degeneration (AMD) is a leading cause of vision loss among people age fifty (50) and older. In AMD, the macula, a small spot near the retina in the back of the ocular globe, is damaged. In patients with AMD, a blurred area in the central vision range appears and grows, eventually resulting in a blind spot in the central vision. Treatments for intermediate and acute AMD include vitamin therapy, such as vitamin C, vitamin E, and supplement therapy, such as zinc, cupric oxide, or lutein and zeaxanthin supplements. However, effective treatments for AMD are still sought.
Conjunctivitis is the infection or inflammation of the transparent membrane (conjunctiva) that lines the eyelid and covers the white part of the eyeball. In conjunctivitis, small blood vessels in the conjunctiva are inflamed and appear to be pink or red.
Conjunctivitis is caused by bacterial or viral infection or by allergies. In infants, an incomplete open tear duct may cause conjunctivitis. Early treatment of conjunctivitis prevents spreading, as certain conjunctivitis conditions can be contagious.
The cannabis plant has many naturally occurring substances that are of great interest in the fields of science and medicine. Isolated compounds from the cannabis plant include Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabichromene (CBC), cannabigerol (CBG), cannabidivarin (CBDV), among other compounds. While THC has psychoactive effects, CBD, CBC, CBG, and CBDV do not. Isolated compounds from the cannabis plant are called cannabinoids. There are a total of eighty-five (85) cannabinoids that have been isolated from the cannabis plant. Many researchers have confirmed the medicinal value of cannabinoids. Cannabinoids have been investigated for possible treatment of seizures, nausea, vomiting, lack of appetite, pain, arthritis, inflammation, and other conditions.
The IUPAC nomenclature of THC is (−)-(6aR,10aR)-6,6,9-trimethyl-3-pentyl-6a,7,8,10a-tetrahydro-6H-benzo[c]chromen-1-ol. CBD's IUPAC nomenclature is 2-((1S,6S)-3-methyl-6-(prop-1-en-2-yl)cyclo-hex-2-enyl)-5-pentylbenzene-1,3-diol). CBC has the IUPAC nomenclature of 2-methyl-2-(4-methylpent-3-enyl)-7pentyl-5-chromenol. These are among the most prominent compounds in the family of compounds extracted from the cannabis plant referred to as cannabinoids.
Cannabinoids can be isolated by extraction or pressing from cannabis plants. Plants in the cannabis genus include Cannabis sativa, Cannabis ruderalis, and Cannabis indica. These plants are the natural sources of cannabinoids. Cannabinoids are also available in synthetic forms. Methods to synthesize cannabinoids in lab settings were discovered and are still currently practiced. Synthetic cannabinoids are more targeted, in that the synthetic compound usually comes isolated without other cannabinoids mixed in.
Nabilone (racemic(6aR,10aR)-1-hydroxy-6,6-dimethyl-3-(2-methyloctan-2-yl)-7,8,10,10a-tetrahydro-6H-benzo[c]chromen-9(6aH)-one), a synthetic cannabinoid, is believed to have fewer undesired side effects than THC. Nabilone mimics the chemical compound structure of THC. THC also exists in synthetic form under the name Dronabinol ((−)-(6aR,10aR)-6,6,9-trimythel-3-pentyl-6a,7,8,10a-tetrahydro-6H-benzo[c]chromen-1-ol)). These synthetic cannabinoids are being investigated for medicinal purposes. The U.S. Food and Drug Administration approved nabilone for treatment of chemotherapy-induced nausea and vomiting. In the United States, nabilone is marketed under the name Cesamet®.
Cannabinoids have neuroprotective properties, especially cannabidiol and cannabigerol (CBG). Glaucoma is essentially the damage of optic nerve, and cannabinoids are useful in treating this damage. Moreover, cannabinoids also lower IOP when consumed by pulmonary absorptions, intraoral, and intravenous applications.
In AMD, wherein macular degeneration is the main cause, cannabinoids have neuroprotective properties and may slow down the degeneration of optic nerves. Regeneration of the macula may be promoted with the use of cannabinoids.
Cannabinoids also have anti-inflammatory and anti-angiogenic properties. These properties may be utilized in ophthalmitis, wherein ophthalmic tissues are infected; or conjunctivitis, wherein ophthalmic membrane tissues are infected and/or inflamed.
Cannabigerol has anti-bacterial and anti-inflammatory properties, with fast acting mechanisms. Cannabidiol is also anti-bacterial, with a minimum inhibitory concentration at between 0.5-1 μg/mL for various Staphylococcus aureus strains. Tetrahydrocannabinol also has anti-inflammatory and anti-bacterial properties.
Various products containing cannabidiol have been marketed in recent years. Cannabidiol may be consumed by ingestion, by inhalation, or by transdermal delivery. THC, CBD, and CBG have been studied for treatment of various indications, including nausea, lack of appetite, pain, epilepsy, etc.